Agroforestry is a land use management system in which trees are grown with agricultural crops to create an annual income while waiting for tree harvest.
Agroforestry is also used to create a more diverse, productive, healthy, and sustainable land-use system. Although thousands of year old, the idea of growing crops with trees is being touted as the new way to combat climate change and alleviate world hunger.
Agroforestry offers many other benefits besides wood and food.
Agroforestry Provides Soil Improvement
In many instances, a symbiotic relationship exists between trees and other plants. Fiddlehead ferns and Trillium flowers provide root fertilizers for temperate forests in Eastern North America, for example. Maple, beech and birch trees prefer acidic soils and typically are found growing along side columbine, wild ginger, flowering dogwood, foxglove, gardenia and huckleberry in the wild. These plants may be dispersed throughout a tree plantation soon after transplant to create an acidic soil pH. Tropical trees grow well with tropical plants like canna, the tropical bird of paradise, dragon tree, hibiscus, bamboo, umbrella trees and impatiens to name a few.
Agroforesty Creates Biodiversity & Ecosystem Development
Tree plantations on their own provide for at least a level of biodiversity, even mono-cultured stands. Many species of birds will thrive in the tree canopy and on the forest floor. A natural “ green manure” is created each year from tree leaves that fall to the forest floor creating an environment for fungi and small creatures that feed on the decaying material. Over-time, non-woody plants germinate from this nutrient rich layer of material creating an understory beneath the upper tree canopy. Small animals will eventually inhabit the understory with larger animals such as deer soon to follow. Within 10 years of transplant, a diversified ecosystem will thrive throughout the plantation due to Agroforestry.
Agroforesty Stabilization & Retains Water
The leaf canopy of a tree plantation retains moisture and regulates temperature, which may be beneficial for understory plants. In drier climates, higher humidic levels may be achieved compared to those outside the plantation. Most understory plants grow better the higher the humidity. Plantation tree roots pull water from the ground. This action multiplied by several thousand trees can make water tables rise so that understory plants can thrive.
In the industrialized west, Agroforestry is in its infancy, however in some tropical areas of the world growing trees and agricultural crops together has been practiced for many generations. In Latin America for example, coffee plants needed to be cultivated under the shade of trees but in the 1960’s new plant breeds where introduced to the region that could grow in the full sun. It soon became apparent that without shade, the new coffee plants required expensive, frequent fertilizing and became susceptible to all kinds of pests. Productivity was also lower. Today, most of these new sun coffee plantations have been abandoned and the land returned to its natural state. Agroforestry would have been the answer.
In more temperate regions of the world, tree farmers are experimenting with combining more traditional agricultural crops with trees.
Growing Trees & Agricultural Crops Together
Many types of vegetables can intermingled throughout a tree plantation, particularly when it is young and the plant canopy hasn’t entirely blocked out the sun. Most types of pole beans will climb the trunk and branches of a young tree, for example. Melons and squash of all types can be planted at the center point between each row of trees. Raspberries, blackberries and currants will thrive between tree rows even as the canopy develops and creates more shade. Many herbs grow well in the acidic soil of a forest floor including parsley, cilantro, basil, mint and rosemary.